This is the no-fluff reference for Rust crossbreeding mechanics. Every rule, weight and layout, condensed for quick lookup mid-wipe. If you want the long-form explanation with examples, read the God Clone Guide instead — this page is built for fast lookup.
Gene weights table
Each gene type votes with a different weight when crossbreeding:
G (Growth) — weight 0.6 — fastest grow time
Y (Yield) — weight 0.6 — bigger harvest
H (Hardy) — weight 0.6 — resists condition swings
W (Water) — weight 1.0 — wins ties, drinks more water
X (Empty) — weight 1.0 — wins ties, no effect
The danger: W and X are 67% heavier per vote than the good genes. A single W parent can override two G or Y parents at the same locus.
Layout: 8 around 1
In a 3×3 large planter, place your candidate seed in the centre and 8 donor parents in the surrounding slots. When the centre plant enters the crossbreed stage, each of its 6 gene slots is voted on independently by the 8 neighbours.
Triangle planter (smaller) is 4 slots: 1 centre + 3 donors. Useful early wipe but offers fewer votes per locus.
Edge slots in a 3×3 only have 5 neighbours, corners only 3. Always keep your candidate in the centre — it gets the most influence.
How a locus is decided
For each of the 6 gene positions, the game does this:
1. Sum the vote weights for each gene type from all neighbours.
2. The highest-weight gene wins — but only if it strictly beats the centre's current gene. If the centre's current gene weight ties or exceeds the donor max, the centre keeps its gene.
3. If two donor genes tie for highest, the game does a 50/50 coinflip between them.
This is why any W or X in the donor pool is dangerous: their 1.0 weight ties (or beats) most G/Y combinations.
The clone window
Crossbreeding genetics are calculated once, when the centre plant first enters the crossbreed stage (the crosshair icon appears). After that, the new genome is locked.
Clone immediately when you see the crosshair. If you wait until ripe, you can still harvest — but you can't get another clone with the new genetics, and any plant grown from a non-cloned seed has its old genome.
Pro tip: keep your cloning hatchet on hotbar slot 1 during a breeding round. The transition from sprawling → crossbreed → ripe is short.
Quick rules of thumb
Six matching donors of the same target gene = guaranteed override (6 × 0.6 = 3.6 weight, beats any reasonable W/X stack).
Three donors with the same gene = strong but not safe — a single W counter beats it.
Mixed parent types in one round = unpredictable. Use the God Clone Planner to run the math.
Filter out D-grade seeds first with the Seed Grader — they hurt more than help.
Common mistakes
Mixing one W parent into a 7-clean planter. The W's tie-weight will win at multiple loci even when outnumbered.
Not cloning at the crossbreed stage. By the time the plant is ripe, the genetics are gone forever from that plant.
Putting your candidate in a corner instead of centre. Corner has 3 neighbours, centre has 8 — 2.7× more votes.
Trying to cross with random low-grade seeds. Two B-grade and a D-grade together usually nets you a worse result than two B-grade alone in a triangle planter.
Want the planner to find your shortest path to GGGYYY? Plug in your seeds and let it work out the optimal layout.